Generally, an X-ray CT imaging apparatus includes an X-ray tube that radiates X-rays onto an object, a detector that detects X-rays having been transmitted through the object, a rotating mechanism unit that rotates with the X-ray tube and the detector mounted thereon, and a computer device that reconstructs data obtained by the detector into image information.
Such a typical X-ray CT imaging apparatus having the above configuration captures tomograms of the object while the rotating mechanism unit rotates around the object. The CT imaging of the object is performed at regular fine angles, and pieces of X-ray projection data obtained when imaging is performed at regular fine angles are reconstructed into sectional image information about the object using mathematical operations such as an iterative reconstruction technique, a back-projection reconstruction technique, or a filtered back-projection reconstruction technique.
In particular, dental CT is a device for obtaining transmitted information while an X-ray tube and an X-ray detector, which are respectively aligned on the left and right sides of an object, rotate in parallel with a ground surface so as to professionally diagnose only specific regions such as the head, neck, jaw and teeth of a patient in dental and oral clinics.
In the case where a specific region of a patient is imaged using dental CT, if images are captured at a fixed magnification ratio regardless of the region to be imaged, the quality of the reconstructed images of the CT may be deteriorated.